a)Hydra referenced in Space Jockey?
Micronauts Hydra Vehicle known to have been released in 1976 also also appears to have been referenced in Giger's space jockey chair.

This works with the understanding that Giger was so used to thinking
about the Micronauts as a point of reference after his Necronom
paintings that integrated it into the Space Jockey design n 1978.

You can look at the images and see enough of the
similarity with the idea of the supports for the telescope and the supports for
the missile launcher.

b)Ribbing pattern on the sideBoth have a strip of ribbing pattern near along the side by the front made up from near enough five segments.

c)Is the Hydra inspired by the Sokar Funerary Barque as well?This
vehicle was also probably inspired by the Sokar Funerary Barque from
the Papyrus of Ani. The chain/rope hanging from the bull horns behind
the antelope head becomes the support for the chair, and perhaps the skirt
worn by the crouched man becomes the seat. The three rudders at the
front become five vertical shapes near to the front of the sides. They
both have a curved top on the sides.

Henu Barque from Papyrus of Aniblack and white image of the Henu Barque from the Papyrus of Ani (source: The Ancient Egyptian Book of the Dead, The British Museum Press)